P1521: IMPROVED CLINICAL OUTCOME OF COVID-19 IN HAEMATOLOGIC MALIGNANCY PATIENTS RECEIVING A FOURTH DOSE OF ANTI-SARS-COV-2 VACCINE: AN EPICOVIDEHA REPORT
Authors: Jon Salmanton-García, Francesco Marchesi, Andreas Glenthøj, Yavuz M. Bilgin, Jens VAN Praet, Julio Dávila-Valls, Sonia Martín-Pérez, Jorge Labrador, Jaap Van Doesum, Iker Falces-Romero, Francesca Farina, Martin Schönlein, Caroline Besson, Verena Petzer, Ildefonso Espigado, Michelina Dargenio, Avinash Aujayeb, Uluhan Sili, Laura Serrano, Laszlo Imre Pinczes, Nick de Jonge, Andrés Soto-Silva, Caterina Buquicchio, Lucia Prezioso, Monia Marchetti, Stef Meers, Alessandro Busca, Paolo Corradini, Martin Hoenigl, Philipp Koehler, Laman Rahimli, Gökçe Melis Çolak, Elena Arellano, Dominik Wolf, Stefanie Gräfe, Emanuele Ammatuna, Caroline Berg Venemyr, Oliver A. Cornely, Livio Pagano
Journal: HemaSphere (2023)

Topic: 30. Infections in hematology (incl. supportive care/therapy) Background: There is a lack of consolidated data has resulted in a general skepticism on anti-SARS-CoV-2 fourth dose efficacy. As a consequence, only few individuals received a fourth dose, despite several data supports the low immunogenicity of anti-SARS-CoV-2 vaccine in pateints with hematological malignancies. Aims: We aim to report the clinical presentation and outcome of COVID-19 occurring in a cohort of HM patients who had previously received a fourth anti-SARS-CoV-2 vaccine dose registered in the EPICOVIDEHA registry. Methods: Any patient included in the EPICOVIDEHA registry was eligible as long as they could fulfill these criteria: a) active HM within the last five years before COVID-19 diagnosis, b) patients ≥18 years old, c) laboratory-based diagnosis of SARS-CoV-2 infection, and d) reception of a fourth anti-SARS-CoV-2 dose before COVID-19 diagnosis. Results: 6867 HM patients with SARS-CoV-2 infection have been registered in the EPICOVIDEHA registry. Of these, 51 (0.7%) were diagnosed with COVID-19 after having received a fourth vaccine dose. Most of those (30/51, 58.8%) were male; median age was 71 years (IQR 65-73) comprising only three patients below the age of 50 years. Twelve patients (12/51, 23.5%) did not present any baseline underlying conditions besides the HM. Lymphoproliferative malignancies were prevalent (47/51, 92%). Most patients had a controlled HM at the time of COVID-19 diagnosis (30, 58.8%). Patients received the fourth vaccine dose at a median of 32 days (IQR 13-54) before COVID-19 diagnosis, almost exclusively mRNA based (50/51, 98%). COVID-19 remained asymptomatic or mild in almost all cases (49/51, 96%), with only one case of critical infection (2%) requiring intensive care. Hospital admission rate was 47.1% with a median hospital stay of 9 days (IQR 5-14). Only 26 patients (51%) received a specific treatment for SARS-CoV-2, with almost all of them (18/26, 69.2%) receiving monoclonal antibodies. Patients were followed up for a median of 65 days (IQR 26-86) and only two died (3.9%) due to COVID-19. Summary/Conclusion: In conclusion, with the caution derived from the limited patient number and the intrinsic nature of this study, our data show favorable clinical presentation and outcome of breakthrough SARS-CoV2 infections in HM who previously received a fourth dose of anti-SARSCoV-2 vaccine. The data suggests that a second vaccine booster may be of particular importance to protect this particularly vulnerable patient population from severe or potentially life-threatening COVID-19. Keywords: Hematological malignancy, COVID-19, Infection, Vaccination